Book Image

Learning RxJava

By : Nield
Book Image

Learning RxJava

By: Nield

Overview of this book

RxJava is a library for composing asynchronous and event-based programs using Observable sequences for the JVM, allowing developers to build robust applications in less time. Learning RxJava addresses all the fundamentals of reactive programming to help readers write reactive code, as well as teach them an effective approach to designing and implementing reactive libraries and applications. Starting with a brief introduction to reactive programming concepts, there is an overview of Observables and Observers, the core components of RxJava, and how to combine different streams of data and events together. You will also learn simpler ways to achieve concurrency and remain highly performant, with no need for synchronization. Later on, we will leverage backpressure and other strategies to cope with rapidly-producing sources to prevent bottlenecks in your application. After covering custom operators, testing, and debugging, the book dives into hands-on examples using RxJava on Android as well as Kotlin.
Table of Contents (14 chapters)

Dealing with SAM ambiguity

At the time of writing this, there is a nuance when Kotlin invokes Java libraries with functional parameters. This problem especially rears its head in RxJava 2.0 when many parameter overloads are introduced. Kotlin does not have this issue when invoking Kotlin libraries but it does with Java libraries. When there are multiple argument overloads for different functional SAM types on a given Java method, Kotlin gets lost in its inference and needs help. Until JetBrains resolves this issue, you will need to work around this either by being explicit or using RxKotlin's helpers.

Here is a notorious example: The zip() operator. Try to do a simple zip here and you will get a compile error due to failed inference:

 

import io.reactivex.Observable

fun main(args: Array<String>) {

val strings = Observable.just("Alpha", "Beta&quot...